<!DOCTYPE html>
<head>
  <style type="text/css">
    #wrapper-div {
      height: 200px;
      overflow-y: scroll;
    }
    iframe {
      height: 1000px;
    }
  </style>
</head>
<body>
  <div id="wrapper-div">
    <iframe src="/cross-site/b.com/title1.html"></iframe>
  </div>
</body>
</html>

